Very poor as a trading simulation, for the many reasons people have already posted. If this didn't have a historical setting with social commentary, I think more people would realize this is a pretty shallow game.
It would be nice if the info boxes explaining the various weapons could be accessed outside of the actual match. It's a little annoying having to rush through it when the clock is ticking.
The developer did an excellent job with map design. Through the lack of a map (mini or otherwise) and the black-and-white, mostly identical imagery, the player feels lost for much of the game. But at the same time, he was careful to make sure that each artifact or important location is tied to the paths, even if loosely. There is no need to go wandering aimlessly in the dark; even the hidden signpost ending has a scavenger hunt feel to it, so it's not unguided. Additionally, I love the indirect storytelling -- it makes you feel like you are really exploring, not just having every detail handed to you. Excellent atmospheric game.
I was going to post saying that it gets a bit tedious, because it does. But the last few levels are actually pretty nice -- less trial and error, and more intelligent assessment. The middle levels, where you just have a mess of pegs and gears, are just boring and (judging from the comments) lead most people to stop playing before they get to the "good" levels. Honestly, I'd remove most of the middle, use the last levels as a new middle, and then mix it up with new gears / obstacles / rules for a new last segment. Would make a tighter, more enjoyable game.
If you'll note, RStein.org is given in the game itself -- it's right on the title screen -- and it's the administrator for that site (Marcel) who made the post that is linked to, saying the account that published this game here is not his. Seems pretty clear to me.
Achievements: Check the credits. Check the 'more games' button. Beat level 19 using the initial gatling. Upgrade everything. Beat everything. Get every AMU.
There's one I'm missing, though, no idea what that is.
If you're having trouble with Loki, try using Valkyrie or Odin. They can both fly around him faster than his spread can fire, so you should be able to avoid getting hit that way. And their overdrives let you lay into him with no reprisal. Only let yourself get hit when your chain gets above 20k, and you'll basically never be out of overdrive. Also, make sure you're using a fast weapon or you won't hit him much. (Excalibur would be ideal.)
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